This invention relates to an autobicycle in which a side portion of an engine is covered by a body side cover, and more particularly to a cooling structure for an engine or some other elements of an autobicycle having a body side cover of the full cover type which continuously covers a side portion of a body from the front to the rear.
Conventionally, it is a common art in autobicycles of the road sport type or the like to cover, with a fairing, a front half portion of a body from a location in front of a dash board to opposite sides of an engine carried between front and rear wheels in order to reduce the air resistance against and the dynamic lift to the autobicycle during running of the autobicycle at a high speed. Some autobicycles employ a full cover system wherein a body is continuously covered by a body side cover including a fairing which covers a front half portion of the autobicycle and a rear cowl which covers a rear half portion of the autobicycle. In such an autobicycle of the full cover type, various wind introducing ports are opened on a body side cover while a flow passage for a running wind is provided in the inside of the body side cover in order to utilize the inside of the body side cover as a kind of wind introducing passage which allows a running wind admitted into the inside of the body side cover to flow smoothly to built-in components such as an engine so as to effectively cool the engine and an inside portion of the autobicycle. This construction will present various good effects including prevention of thermal wear and interception of mechanical noises and hat wind. An autobicycle of such construction is disclosed, for example, in Japanese patent application No. 61-124775.
One of principal heat sources within a body side cover is the engine. In addition, when an autobicycle is of the water cooled type, also a radiator is one of the principal heat sources. If the inside of the body side cover is heated to a high temperature by the heat sources, a thermal influence will occur on functional parts and so on within the body side cover other than the heat sources. However, where the engine has a high output power, the amount of heat generated thereby is large. Accordingly heat is apt to remain within the body side cover. Particularly where the autobicycle is of the full cover type, the remaining heat is large in amount. Therefore, where heat sources such as an engine and some other functional parts and so on are covered with a body side cover, it is necessary to improve the effect of cooling the inside of the body side cover in order to reduce a thermal influence to be had on such other functional parts and so on as low as possible. To this end, the wind introducing area within the body side cover may be increased to improve the cooling efficiency, but it cannot be increased freely and is naturally restricted within a fixed range because there is an artificial restriction, for example, in the step width.